I am desperate to get advice how to obtain a divorce in china

I married for the sake of my son (UK) passport on my visa , my wife is chinese , sorry to say not so nice , we had problems from the start but I tried working them out , but not to be , we bought a appartment , my son live with me and ayi for 5 yrs ,I PAY ALL things , she is in a diffrent city as her own life and lovers , I just want it to end for my son sake , She agreed to split the appartment 50 - 50 but demanding I pay alomoney for full 10 years up front which i think is rubbish she so bad with money ,I do not trust , she refuse so she say to agree any other terms , We have not had any pyhiscal contact in over 4 years she admits this , she never pay anything to my son ,I dont wan t to give him to her she only care money , she even put in writing if I gave her the appartment I have my son (8million) this can not right.